(44c) Application of Aggregation Thermodynamics and Molecular Characterization to Study Asphaltene Precipitation of Bituminous Crude Oils

Application of Aggregation Thermodynamics and Molecular Characterization to Study Asphaltene Precipitation of Bituminous Crude Oils

Md Rashedul Islam, Yifan Hao, Meng Wang, and Chau-Chyun Chen

Department of Chemical Engineering, Texas Tech University

Abstract

Addition of paraffinic feedstock to bituminous crude oil significantly impairs the solvent power of crude oil. The content and nature of paraffins in the blend determines the asphaltene precipitation behavior, i.e. onset point, and yield. Comprehensive thermodynamic modeling offers the necessary tool to understand and track the compatibility of heavy crude oils with paraffinic feedstock, and to predict asphaltene precipitation onset and yield. Recently, an aggregation thermodynamic framework [1] developed from Yen-Mullins hierarchy model for asphaltene [2] has been shown to successfully predict asphaltene precipitation from a wide spectrum of solvent mixtures. Furthermore, a molecule based characterization approach has been utilized to represent Cold Lake bitumen with real hydrocarbon molecules and a refined NRTL-SAC activity coefficient model [4] successfully applied to predict asphaltene precipitation from mixing Cold Lake bitumen with n-alkanes [5]. In this work, this methodology is further demonstrated with two additional heavy oils, i.e., Athabasca and Peace River.

References

[1] M. Wang, Y. Hao, M. R. Islam, and C.-C. Chen, "Aggregation thermodynamics for asphaltene precipitation," AIChE Journal, vol. 62, pp. 1254-1264, 2016.

[2] O. C. Mullins, "The Modified Yen Model†," Energy & Fuels, vol. 24, pp. 2179-2207, 2010.

[3] C.-C. Chen and H. Que, "Method of Characterizing Chemical Composition Of Crude Oil For Petroleum Processing," US Patent Application Number: 2013/0185044, July 18, 2013.

 [4] Y. Hao, M.R. Islam, M. Wang, and C.-C. Chen, "A refined Non-Random Two-Liquid segment activity coefficient model for solubility modeling," manuscript in preparation (2016)

[5] M.R. Islam, Y. Hao, M. Wang, T. Kirkes, and C.-C. Chen, "Application of molecular characterization to bituminous crude oil to study asphaltene precipitation," presented at the 2016 AIChE Annual Meeting, San Francisco, CA., November 12-17, 2016.